logger, compiler logic, sse endpoints

backend/backend.go

@@ -2,26 +2,45 @@ package backend
 
 import (
 	"os"
+	"os/exec"
 	"path/filepath"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"git.noctra.dev/noctra/servtex/globals"
+	"time"
 )
 
+func getLocalTime() time.Time {
+	timezone, _ := time.LoadLocation(globals.AppConfig.Timezone)
+	return time.Now().In(timezone)
+}
+
+func getLocalTimePretty() string {
+	return getLocalTime().Format("02.01.2006 15:04")
+}
+
+func LogLine(message string) {
+	logline := "\n" + getLocalTime().Format(time.RFC3339) + " - " + message
+	globals.LogFile.WriteString(logline)
+}
+
 // Helper for configReader() that does the actual reading
+// Also validates the populated fields
 func configReaderParse(filePath string, configOptionStorage *globals.Config) error {
 	jsonData, err := os.ReadFile(filePath)
 	if err == nil {
 		err = json.Unmarshal(jsonData, &configOptionStorage)
 		if err != nil { 
-			// log error unmarshal failure
 			return errors.New("Config file could not be read")
 		}
 	} else {
 		return errors.New("Config file does not exist")
 	}
 
+	return configValidator(*configOptionStorage)
+}
+
+func configValidator(config globals.Config) error {
 	return nil
 }
 
@@ -48,34 +67,52 @@ func ConfigReader(configFileName string, configOptionStorage *globals.Config) er
 	err = configReaderParse(path, configOptionStorage)
 	if err == nil { return nil }
 
-	// log error no config file found
-	return errors.New("Configuration file not found or json parsing error")
+	return err 
 }
 
 // Watches a specified directory and calls a function on change
 // Optionally, a minimum time to wait for consecutive changes can be specified
 func ChangeWatch(path string, callOnChange func()) {
+	LogLine("File change noticed")
 }
 
 // Intended to be run as goroutine
-func LatexCompile(config *globals.Config) error {
-	if !config.ExecutionLock.TryLock() {
+func LatexCompile(config globals.Config, execution *globals.LatexExecution) error {
+	if !execution.ExecutionLock.TryLock() {
+		LogLine("LaTeX execution already underway")
 		return errors.New("Execution already in progress")
 	}
+	LogLine("LaTeX execution started")
+	execution.ExecutionState = "Started"
 
-	var latexCommand string
+	var latexCommand *exec.Cmd
 	switch config.LatexEngine {
 		case "lualatex":
-		latexCommand = fmt.Sprintf(
-			"lualatex -output-directory=%s -jobname=servtex %s",
-			config.LatexOutputPath,
-			config.LatexSourceFilePath,
-		)
-
+			latexCommand = exec.Command(
+				"lualatex", 
+				"-output-directory=" + config.LatexOutputPath, 
+				"-jobname=servtex", 
+				config.LatexSourceFilePath,
+			)
+		default:
+			execution.ExecutionState = "Unknown Latex Engine"
+			execution.Output = []byte{}
+			execution.Timestamp = getLocalTimePretty()
+			execution.ExecutionLock.Unlock()
+			return errors.New("Unknown Latex Engine")
 	}
-	
-	fmt.Sprintf(latexCommand) // placeholder for compilation
-	config.ExecutionLock.Unlock()
+
+	execution.ExecutionState = "Running"
+	stdout, err := latexCommand.Output()
+	if err != nil { 
+		execution.ExecutionState = "Failed"
+		return err 
+	}
+
+	execution.Output = stdout
+	execution.Timestamp = getLocalTimePretty()
+	execution.ExecutionState = "Done"
+	execution.ExecutionLock.Unlock()
 	return nil
 }
 

config.json

@@ -9,5 +9,6 @@
 	"webserverDomain": "localhost:9876",
 	"webserverSecure": false,
 	"certificatePath": "",
-	"certificateKeyPath": ""
+	"certificateKeyPath": "",
+	"timezone": "Europe/Berlin"
 }

frontend/templates/body.html

@@ -12,7 +12,7 @@
         <iframe class="pdf-frame" src="servetex.pdf?ts=0" hx-sse="connect:/sse/pdf" hx-swap="outerHTML"></iframe>
       </div>
     </div>
-      <div class="command-out">
+      <div class="command-out" hx-sse="connect:/sse/status" hx-swap="innerHTML">
         compile start
         compile file-x
         compile file-y

frontend/webserver.go

@@ -1,2 +1,32 @@
 package frontend
 
+import (
+	"net/http"
+	"fmt"
+	"git.noctra.dev/noctra/servtex/globals"
+)
+
+// Publishes Meta Information relating to last execution
+// Does not use contained Mutex, ignore warning
+func SSEStatus(writer http.ResponseWriter, request *http.Request) {
+	writer.Header().Set("Content-Type", "text/event-stream")
+	writer.Header().Set("Cache-Control", "no-cache")
+	writer.Header().Set("Connection", "keep-alive")
+
+	fmt.Fprintf(writer, "data: Execution Time:  %s\n", globals.LatexExec.Timestamp)
+	fmt.Fprintf(writer, "data: Execution State: %s\n\n", globals.LatexExec.ExecutionState)
+
+	writer.(http.Flusher).Flush()
+}
+
+func SSEOutput(writer http.ResponseWriter, request *http.Request) {
+	writer.Header().Set("Content-Type", "text/event-stream")
+	writer.Header().Set("Cache-Control", "no-cache")
+	writer.Header().Set("Connection", "keep-alive")
+
+	fmt.Fprintf(writer, "data: Execution Time:  %s\n", globals.LatexExec.Timestamp)
+	fmt.Fprintf(writer, "data: Execution State: %s\n\n", globals.LatexExec.ExecutionState)
+
+	writer.(http.Flusher).Flush()
+}
+

globals/memory.go

@@ -1,6 +1,9 @@
 package globals
 
-import "sync"
+import (
+	"os"
+	"sync"
+)
 
 type Config struct {
 	// general
@@ -17,9 +20,18 @@ type Config struct {
 	WebserverSecure		bool  	`json:"webserverSecure"`
 	CertificatePath		string	`json:"certificatePath"`
 	CertificateKeyPath	string	`json:"certificateKeyPath"`
-
-	// to prevent competing compiles, not actual configuration
-	ExecutionLock		sync.Mutex
+	Timezone		string	`json:"timezone"`
 }
 var AppConfig Config
 
+
+type LatexExecution struct {
+	ExecutionLock	sync.Mutex
+	ExecutionState	string
+	Timestamp	string
+	Output		[]byte
+}
+var LatexExec LatexExecution
+
+var LogFile *os.File
+

go.mod

@@ -1,3 +1,5 @@
 module git.noctra.dev/noctra/servtex
 
 go 1.25.5
+
+require github.com/tmaxmax/go-sse v0.11.0

go.sum

@@ -0,0 +1,2 @@
+github.com/tmaxmax/go-sse v0.11.0 h1:nogmJM6rJUoOLoAwEKeQe5XlVpt9l7N82SS1jI7lWFg=
+github.com/tmaxmax/go-sse v0.11.0/go.mod h1:u/2kZQR1tyngo1lKaNCj1mJmhXGZWS1Zs5yiSOD+Eg8=

main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"os"
-	//"log/slog"
 	"git.noctra.dev/noctra/servtex/globals"
 	"git.noctra.dev/noctra/servtex/backend"
 	//"net/http"
@@ -14,8 +13,9 @@ import (
 //	1 - config file could not be read
 func main() {
 	err := backend.ConfigReader("config.json", &globals.AppConfig)
-	if err != nil {
-		os.Exit(1)
-	}
+	if err != nil { os.Exit(1) }
+
+	globals.LogFile, err = os.Open(globals.AppConfig.LogFilePath)
+	if err != nil { os.Exit(2) }
 }